Take-up mechanism for knitting machines



Aug. 28, 1962 H. c. NOE 3,050,972

TAKE-UP MECHANISM FOR KNITTING MACHINES Filed April 4, 1958 2 Sheets-Sheet 1 ATTORNEY Aug. 28, 1962 H. c. NOE 3,050,972

TAKE-UP MECHANISM FOR KNITTING MACHINES Filed April 4, 1958 2 Sheets-Sheet 2 Th7, C5

ATTORNEY 3,950,972 TAKE-UP MECHANlSl'vl FUR KNHTTIING MACHH IE Harold C. Noe, Upper Montclair, NJ assignor to iiidde Textile Machinery Corporation, Bloomfield, Ni, a

corporation of Delaware Filed Apr. 4, W58, Ser. No. 726,432 8 Claims. (Ci. 66--l52) The present invention relates to knitting machines, and, more particularly, to an improved fabric take-up mechanism for such machines.

Knitting machines customarily include a fabric take-up mechanism which regulates the length of the knitted stitches in the fabric by placing a controlled tension on the fabric as it leaves the knitting line. Generally, the take-up mechanism comprises a plurality of driven rolls which grip the fabric and draw it warpwise away from the knitting line, whereby the length of the stitches formed can be controlled by the speed at which the rolls are driven.

During the knitting operation, the warp threads at the knitting line are alternately tensioned and released because the knitting needles hold the warp threads against the pull of the take-up while forming a stitch and then cast them off before forming the next stitch.

The section of fabric between the knitting line and the point at which the fabric contacts the first roll tends to stretch as tension is applied. This stretching action causes loose selvages in the fabric formed, and since the degree to which the fabric is stretched depends upon the length of the aforementioned section of fabric, it is essential that the distance between the knitting line and the point of contact of the fabric with the roll be kept at a minimum.

The minimum distance between the knitting line and the point of contact with the first take-up roll is controlled by the diameter of that roll, therefore, it is desirable to use relatively small diameter take-up rolls. As machines are made of greater width, the increase in length of the take-up rolls decreases their rigidity to a point where the aforementioned cyclic application and release of tension during the knitting operation causes the rolls to deflect transversely at the middle thereof as tension is applied and spring back when the tension is released. As a result, the roll oscillates and causes the threads at the middle of the fabric to be placed under a different degree of tension than the threads near the edges of the fabric. This variation in tension produces a fabric in which the stitch length varies across the width of the fabric to form shade marks, and, in severe cases, causes threads to break.

Accordingly, an object of the present invention is to provide a take-up mechanism which provides uniform tension throughout the width of the fabric.

Another object is to provide a take-up mechanism wherein the first take-up roll in particular is prevented from oscillating.

A further object is to accomplish the foregoing in a simple, practical and economical manner.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

In accordance with this invention, the foregoing objects are accomplished by providing a take-up mechanism including a take-up roll, a bracing roll in contacting relationship with the take-up roll to prevent oscillation thereof, and bearing means intermediate the ends of the take-up roll for rotatably mounting the bracing roll.

3,950,972 Patented Aug. 28, 1962 A preferred embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part Of the specification wherein:

FIG. 1 is a rear elevational view of a take-up mechanism in accordance with the present invention.

FIG. 2 is a sectional view taken along the line 2-2 on FIG. 1 illustrating the knitting elements and the path of the fabric as it leaves the knitting line.

FIG. 3 is an enlarged sectional view taken along the line 3--3 on FIG. 1 illustrating a detail of the mechamsm.

Referring to FIGS. 1 and 2 of the drawing in detail, there is shown a take-up mechanism in accordance with the present invention for a knitting machine having a frame in (FIG. 1), and knitting elements including yarn or thread guides 11, needles 12, and needle bed structure 13 adapted to produce fabric F at the knitting line K (PEG. 2).

The take-up mechanism generally comprises two driven rolls 14 and 15, an idler take-up roll 16 commonly referred to as a pinch roll, a bracing roll 17, and bearing devices 19 for supporting the bracing roll 17.

The driven rolls l4 and are each supported at their ends by bearings provided in the frame 10 of the knitting machine, and are each provided with a covering 13 to aid in gripping the fabric and a gear 21 secured thereto adjacent one end thereof. The rolls 14 and 15 are rotated in same direction (as indicated by the arrows in FIG. 2) by a driven chain (not shown) which engages each of the gears 21. The idler roll 16 is supported by the rolls 14 and 15 and cooperates with the rolls l4 and 15 to grip the fabric F therebetween as shown in FIG. 2.

The bracing roll 17 is positioned beneath the take-up rolls 1d and 15 to provide support for these rolls throughout their length, and is adapted to be lowered so that the fabric F may be threaded about the take-up rolls. Each end of the roll 17 is provided with a section 22 of reduced diameter which are positioned in slots '23 (FIG. 3) formed in members 24 attached to the frame 10 to guide the roll during vertical movement thereof. A gear 25 is mounted on one of the end sections 22 of the roll 17 and engages each of the gears 21 when the roll 17 is in its raised position.

The roll 17 is supported at spaced points throughout its length by the bearing devices 19 which provide the sole support for the roll. Each bearing device includes a frame member 26 supported by the floor or the base of the machine, a plate 27 adjustably mounted on the member 26 by means of bolts 28 and elongated slots 29 provided in the plate, an arm 30 pivotally attached at one end to the plate 27, a cam mechanism 31 adjustably supporting the free end of the arm 30, and a saddle 32 resting on the free end of the arm 30 and supporting the roll 17.

The cam mechanism 31 comprises a rod 34 passing through and supported by a plurality of brackets 35 attached to the frame members 26, a handle 36 for rotating the rod 34-, and cams 37 rigidly attached to the rod 34 for rotation therewith and positioned beneath the free end of the arms 36? to provide support therefor. The cams 37 are provided with a cam surface 38 adjacent the periphery of the rod 34 and a cam surface 39 spaced from the rod 34, to allow the arm 30 to be supported in either of two positions.

The saddle 32 has an arcuate upper surface 40 which is provided with a slot 41 in which a shoe 42 of Teflon or similar material is positioned to provide a low friction bearing surface on which the roll 17 revolves. A pin 44 is provided on the lower end of the saddle and a nut 4-5 threaded on the pin bears on the upper surface of the arm 30 and provides a means of adjusting the distance from the shoe 42 to the upper surface of the arm 30.

When the knitting machine is being operated, the bracing roll 17 is in its raised position as shown in FIG. 2. The chain (not shown) drives the take-up rolls 14 and 15 in the direction indicated, and the bracing roll 17 1s driven through the gear in the opposite direction, as indicated. The fabric F is gripped between the idler ro l 16 and the take up rolls 14 and 15, and between the bracing roll 17 and the rolls 14 and 15, and is drawn from the knitting line K under a tension controlled by the speed at which the take-up rolls are rotated. The bracing roll 17 prevents the rolls 14 and 15 from oscillating or vibrating, by supporting them throughout their length and thereby, prevents the rolls from producing the uneven tension which causes uneven stitches.

In order to initially thread the fabric F around the rolls 14, 15, and 16, the handle 36 is used to rotate the bar 34 and the cams 37 in a counterclockwise direction (as viewed in FIG. 2) until the bottom of the free end of the arm is resting on the cam surface 38. The roll 17 is then spaced from the rolls 14 and 15 and the fabric F can be easily threaded around the takeup rolls. In order to place the mechanism in operating condition, the cam 37 is rotated to the position shown in FIG. 2 with the free end of the arm 30 resting on cam surface 39. If necessary, the nut 45 may be used to provide a fine adjustment to obtain the correct vertical positioning of the roll 17 with respect to the rolls 14 and 15. Also, the position of the plate 27 may be changed to provide the correct horizontal positioning of the saddle 32 with respect to the roll 17.

From the foregoing description, it will be seen that the present invention provides a take-up mechanism which is simple, practical and economical, and which produces a uniform tension throughout the width of the fabric by preventing the take-up roll from oscillating or vibrating.

While the invention has been described herein for use in connection with a knitting machine by Way of example, it will be understood that it may be used wherever similar fabric take-up problems exist.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and Without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in any limiting sense.

I claim:

1. In a take-up mechanism for a cloth fabric forming machine the combination of a rotatably mounted take-up roll adapted to engage and operate on a sheet f cloth fabric, a bracing roll in contacting relationship with said take-up roll to prevent oscillation of said take-up roll, and a plurality of bearing means intermediate the ends of said take-up roll for rotatably mounting said bracing roll, at least one of said bearing means being positioned to be intermediate the edges of a sheet of cloth fabric operated on by said take-up roll.

2. Mechanism according to claim 1, including means for driving said rolls at one end thereof.

3. Mechanism according to claim 1, wherein said bearing means constitutes a plurality of arcuate shoes.

4. Mechanism according to claim 1, including means for producing relative motion between said take-up roll and said bracing roll to space said bracing roll from said take-up roll.

5. in a take-up mechanism for a cloth fabric forming machine the combination of a take-up roll adapted to engage and operate on a sheet of cloth fabric, means for rotatably mounting said take-up roll at each end thereof, a bracing roll in contacting relationship with said takeup roll to prevent oscillation thereof, and movable means supporting said bracing roll including a plurality of bearin means acting on said bracing roll intermediate the ends of said take-up roll whereby said bracing roll may be moved into and out of contact with said take-up roll, at least one of said bearing means being positioned to be intermediate the edges of a sheet of cloth fabric operated on by said take-up roll.

6. In a take-up mechanism for a cloth fabric forming machine the combination of a take-up roll adapted to engage and operate on a sheet of cloth fabric, means for rotatably mounting said take-up roll at each end thereof, a bracing roll beneath said take-up roll and in contacting relationship therewith for supporting the same intermediate the ends thereof, a plurality of bearing means intermediate the ends of said take-up roll for rotatably mounting said bracing roll, at least one of said bearing means being positioned to be intermediate the edges of a sheet of cloth operated on by said take-up roll, and vertically moveable means for supporting said bearing means, whereby said bracing roll may be raised and loW- ered with respect to said take-up roll.

7. Mechanism according to claim 6, including means adjacent each end of said bracing roll for guiding said bracing roll during vertical movement, and gears on said take-up roll and said bracing roll adapted to mesh and unmesh in response to vertical movement of said bracing roll.

8. In a take-up mechanism for a cloth fabric forming machine the combination of a first take-up roll, a second take-up roll parallel to said first roll, said rolls being adapted to engage and operate on a sheet of cloth fabric, means for rotatably mounting each of said take-up rolls, a bracing roll in contacting relationship with both of said take-up rolls to prevent oscillation of said take-up rolls, a plurality of bearing means intermediate the ends of said take-up roll for rotatably supporting said bracing roll, at least one of said bearing means being positioned to be intermediate the edges of a sheet of cloth fabric operated on by said take-up rolls, and means for moving said bracing roll With respect to said take-up rolls.

References Cited in the file of this patent UNITED STATES PATENTS 1,629,850 Trainer May 24, 1927 2,219,797 Wattie Oct. 29, 1940 2,618,295 Bahan Nov. 18, 1952 2,780,840 Ude Feb. 12, 1957 2,800,012 Goetz et a1. July 23, 1957 2,835,540 Jorgensen May 20, 1958 FOREIGN PATENTS 374,954 Great Britain June 20, 1932 

